1. Field of the Invention
This invention relates to instruments or gauges for us in vehicles, and in particular to instruments or gauges that provide feedback detectable by the peripheral vision of a driver when vehicle operating parameters, such as engine speed, temperature, pressure, and voltage, are in a critical range. The instruments or gauges of the invention are especially suitable for use in racing vehicles that meet standards of the National Association for Stock Car Auto Racing (NASCAR), although they may also be used in other types of racing and non-racing vehicles.
The instruments or gauges of the invention may include one or more of the following types of instruments or gauges and/or features:                a. A tachometer that not only includes a primary numeric display, but also a secondary display made up of a plurality of discrete lights of different colors, the colors indicating whether the engine speed of a vehicle is within a relatively narrow range of engine speeds acceptable for the roadway leading from a race track to service areas, known as “pit road,” the high and low limits of the range being adjustable to meet pit road requirements at different tracks;        b. An instrument or gauge having a background that illuminates to indicate critical sensor readings;        c. An instrument or gauge having improved handling of sensor abnormalities to prevent false readings;        d. A non-linear analog gauge for a motor vehicle, such as an oil pressure, temperature, or voltage gauge, having a higher resolution in a particular range of interest, and a lower resolution outside that range;        e. A boost pressure gauge that facilitates entry of gear information for use in traction control; and        f. A teach and learn feature enabling synchronization of gauges, such as fuel sensors, speedometers, and tachometers, to different sensor inputs.        
2. Description of Related Art
The present invention is especially suitable for use in racing vehicles that meet standards of the National Association for Stock Car Auto Racing (NASCAR). Vehicles that comply with the standards set by NASCAR are modified production automobiles that have been stripped of non-essential devices and instruments in order to reduce the weight of the vehicles, and to make room for specialized safety equipment and devices necessary to operation of the vehicle at very high speeds. The nature of NASCAR racing, and in particular the high speeds and close proximity at which the vehicles are driven, requires the driver to devote maximum attention to the track and other vehicles, since any lapse in attention can have catastrophic consequences.
A. The Pit Road Problem
One of the instruments that is typically removed from a NASCAR racing vehicle is the speedometer. Generally, race car drivers seek to drive as fast as possible, and therefore do not require a speedometer. However, one area where more precise speed control is essential is “pit road,” which is the roadway leading from the track to individual pit areas where cars are serviced during a race. Because their vehicles lack a speedometer, drivers must rely on the tachometer to control the speed of the vehicle. This results in the problem that the driver must divide attention between the roadway and the tachometer.
Conventional tachometer displays are extremely difficult to follow solely through peripheral vision, and since the penalties for exceeding the pit road speed limit for a particular track are severe, drivers tend to drive at an engine speed that is lower than optimal, causing the driver to risk loss of position in a race by prolonging the time spent off the track in the pit area. If the driver attempts to keep the engine speed closer to the pit road limit by spending more time observing the tachometer, the driver risks running into a vehicle entering pit road from one of the pit areas. These problems are compounded by differences in the permitted speed for different tracks, which depend on the configuration of the pit road and local conditions, and also because the relationship between vehicle and engine speed can vary, necessitating that a certain “fudge” factor be built into the engine speed calculations, making it even more difficult for the driver to control engine speed by “feel” rather than by observing the tachometer.
To solve this problem, the invention proposes to use the “secondary display” of a conventional racing tachometer to provide an indication of engine speeds that can be monitored through the peripheral vision of a driver in order to determine when the engine speed is approaching the pit road maximum, and which furthermore may be adjusted for different tracks and conditions. The “secondary display” of a racing tachometer is an array of multicolored LEDs that typically is progressively illuminated as a driver approaches a shift point, in order to assist the driver in determining the optimal engine speed at which to change gears. The present invention modifies the conventional secondary display to operate at engine speeds lower than those including shift points, and further by making the range of indicated engine speeds adjustable to account for different tracks and pit road conditions.
B. The Hazard Alert/Warning Problem
Another problem addressed by the present invention is the problem of alerting the driver to conditions that require immediate attention. During a race, safety hazards, such as damage to a vehicle caused by flying debris, can arise very suddenly and require an extremely short reaction time on the part of the driver. As a result, instruments and gauges are required to clearly indicate when a parameter has become critical. Conventionally, this is accomplished by providing red and green LEDs on the instrument or gauge to indicate critical conditions. However, the visual distractions and noise that occurs during normal racing are such that the driver may not notice the conventional warning in time to take action. Furthermore, problems that have about to become critical may only be indicated by the conventional analog display, which is difficult to read without in fine enough detail to indicate the developing hazard. As a result, extra measures are required to bring a potential hazard to the attention of the driver, and also to enable the driver to more easily determine whether a hazardous condition is developing.
The present invention addresses this problem in two ways. The first involves utilizing background lighting for the face of the instrument, and preferably flashing of the background lighting, to more visibly indicate hazards and potential hazards. The second, which may be referred to as the “non-linear” gauge solution, involves modifying analog gauges of various types to have different resolutions, with a higher resolution in the range of particular interest to the driver. According to the non-linear gauge solution, the scale of the analog gauge, i.e., the distance on the gauge that indicates a unit of the parameter being measured, is increased in the range of interest, so that the driver can more easily track small changes in the parameter that might indicate a potential hazard.
C. The False Alarm Problem
In order to avoid false alarms, it is conventional for an instrument with a hazard indicator provide an indication of sensor malfunction due to loss or interruption in a sensor signal. To prevent false alarms, it is also conventional to delay the hazard indication for a predetermined time or predetermined number of samples after a sensor indicates a potential hazard. After the predetermined time or number of samples, the sensor is considered to be defective and an indication thereof is provided to the driver. However, if the delay time is too great, the driver may not be given adequate notice of the loss of a sensor, while if the delay time is too short, false alarms may still occur.
The present invention addresses this problem by reducing the number of samples required for shutdown and at the same time adding an immediate start-up or reset function that deactivates the defective sensor indication as soon as a signal from the sensor is received.
D. The Boost Pressure/Traction Control Problem
At low speeds, it is desirable to limit the boost function of a turbo charger by reducing boost pressure, so as to prevent spinning of a vehicle's wheels from excess turbocharging. However, since the tachometer and manifold absolute pressure (MAP) inputs to the conventional boost controller do not provide a clear indication as to what gear the vehicle is in, automated traction control adapters are conventionally complicated and expensive.
The present invention solves this problem by adapting a boost pressure gauge to enable manual setting of engine speed and MAP setpoints, that can be used to limit boost pressure at low speeds. In particular, the invention provides a procedure by which a driver presses a button or buttons on the gauge to establish engine speed and MAP setpoints when certain engine speeds are reached, the setpoints being used to limit boost and thereby provide traction control in lower gears, and a tachometer adapted for such input.
E. The Gauge Synchronization Problem
This problem results from the fact that different sensors have different outputs. For example, fuel level sensors use different resistances to indicate different fuel levels. As a result, a typical fuel gauge can only be used with a specific type of fuel sensor. The present invention provides a simple way to synchronize or calibrate a gauge with respect to different sensors.